Import group from external blend file
This loads group "Head" from file mouth.blend.  The group can be added to the scene as a group instance.

with bpy.data.libraries.load("/home/batfinger/3DModels/mouth.blend") as (df, dt):
    dt.groups = ['Head']


In your case you will load group "house00" from file myHouseModel.blend

How to add a group instance is covered here Add a group instance with python